Students must start practicing the questions from CBSE Sample Papers for Class 11 Informatics Practices with Solutions Set 3 are designed as per the revised syllabus.

CBSE Sample Papers for Class 12 Informatics Practices Set 3 with Solutions

Time Allowed: 3 hours
Maximum Marks: 70

General Instructions:

  1. All questions are compulsory.
  2. Answer the questions after carefully reading the text.
  3. Student has to answer only one question where choice is given.
  4. All programming questions have to be answered with respect to Python only.
  5. In Python indentation is mandatory; however, number of spaces used for indenting may vary.
  6. In SQL related questions – semicolon should be ignored for terminating the SQL statements,
  7. Use of calculators is not permitted.

SOLVED

Multiple Choice Question:

Question 1.
(i) Which of the following is system software? [1]
(A) Operating system
(B) Compiler
(C) Utilities
(D) All the these
Answer:
(B) Compiler
Explanation: System software is a type of computer program that is designed to run a computer’s hardware and application programs. E.g. Language Translator (Compiler, Interpreter, Assembler), Utility Software, Operating System [1]

(ii) Which of the following is True regarding loops in Python? [1]
(A) Loops should be ended with keyword “end”.
(B) No loop can be used to iterate through the elements of strings.
(C) Keyword “break” can be used to bring control out of the current loop.
(D) Keyword “continue” is used to continue with the remaining statements inside the loop.
Answer:
(B) No loop can be used to iterate through the elements of strings.
Explanation: Keyword break can be used to bring control out of the current loop statement is True regarding loops in Python. [1]

(iii) ______ ensures that for every value of a Foreign key, there is a matching value of the Primary key. [1]
(A) Entity integrity
(B) Domain Integrity
(C) Attribute integrity
(D) Referential Integrity
Answer:
(D) Referential Integrity
Explanation: Data integrity falls into the following categories Entity Integrity, Domain Integrity, Referential Integrity. [1]

(iv) Which data type is used to store the character string in SQL? [1]
(A) Char
(B) Int
(C) Float
(D) Decimal
Answer:
(A) Char
Explanation: CHAR(n) specifies character type data of length n where n could be any value from 0 to 255. CHAR is of fixed length, means, declaring CHAR (10) implies to reserve spaces for 10 characters. If data does not have 10 characters (e.g., ‘city’ has four characters), MySQL fills the remaining 6 characters with spaces padded on the right. [1]

(v) The ______ providers can offer different kinds of computing infrastructure, such as servers, virtual machines (VM), storage and backup facility, network components, operating systems or any other hardware or software. [1]
(A) SaaS
(B) PaaS
(C) IaaS
(D) None of the these.
Answer:
(C) IaaS
Explanation: Infrastructure as a service (IaaS) is a system of cloud computing that delivers virtualized computing resources over the internet. IaaS is one of the three main categories of cloud computing services, together with software as a service (SaaS) and platform as a service (PaaS) [1]

CBSE Sample Papers for Class 11 Informatics Practices Set 3 with Solutions

Question 2.
(a) Which software acts as a mediator between the operating system and the device ? [1]
Answer:
(a) Device deriver(b) [1]

(b) Differentiate between Dynamic RAM and Static RAM. [2]
Answer:

Dynamic RAM Static RAM
It must be refreshed continually to store information It need not be refreshed periodically
DRAM is made up of memory cells where each cell is composed of one capacitor and one transistor It uses multiple transistors for each memory cell. It does not use capacitor.

(c) What do you mean by mouse? [2]
Answer:
A mouse is a small device that a computer user pushes across a desk surface in order to point to a place on a display screen and to select one or more actions to take from that position. The mouse first became a widely-used computer tool when Apple Computer made it a standard part of the Apple Macintosh. Today, the mouse is an integral part of the graphical user interface (GUI) of any personal computer. The mouse apparently got its name by being about the same size and color as a toy mouse. [2]

(d) Explain functions of an operating System. [4]
OR
How do different components of a computer communicate with each other?
Answer:
Important functions of an operating System:

• Security: The operating system uses password protection to protect user data and similar other techniques. it also prevents unauthorized access to programs and user data.

• Control over system performance: Monitors overall system health to help improve performance. records the response time between service requests and system response to having a complete view of the system health. This can help improve performance by providing important information needed to troubleshoot problems.

• Job accounting: Operating system Keeps track of time and resources used by various tasks and users, this information can be used to track resource usage for a particular user or group of users.

• Error detecting aids: The operating system constantly monitors the system to detect errors and avoid the malfunctioning of a computer system. [4]
OR
A computer system primarily comprises of different components such as central processing unit, input/output devices and memory unit. All these components function together as a single unit to deliver the desired result. Input devices send the data or information through keyboard, mouse, scanner etc. CPU transfers instructions and input data from main memory to registers. Output unit sends the processed results to the user. Memory unit is responsible to store processed results on a temporary or permanent basis.

Question 3.
(a) Write the advantage of script mode. [1]
Answer:
(a) Editing your script is easier in script mode. [1]

(b) What is the difference between the values True, False and true, false? [1]
Answer:
True, False represent Boolean values while true, false represent the truthness of a value in general i.e, the truth values. [1]

(c) What is the use of bit wise operator? [1]
Answer:
Bit wise operators are used to perform bit operation. [1]

(d) What is iteration? [1]
Answer:
Each time, when the loop body gets executed, is called iteration. [1]

(e) What will be the following code print? for i in range (1,6):
forj in range (1,5):
print i * j,
print [2]
OR
How can the members of a list accessed in Python?
Answer:
Output
1 2 3 4
2 4 6 8
3 6 9 12
4 8 12 16
5 10 15 20 2
OR
To access members of a list, we can use indices or slicing to access multiple members at a time.
e-g.,
list1 = [‘physics’, ‘chemistry’, 1997, 2000]
list2 = [1, 2, 3, 4, 5, 6, 7]
print (“list1 [0]:”, list1 [0])
print (“list2 [1: 5]:”, list2 [1: 5])
Output:
list1[0]: physics
list2[1: 5]: [2, 3, 4, 5] [2]

(f) Write a Python program to input ‘n’ names and phone numbers to store it in a dictionary and to input any name and to print the phone number of the particular name. [4]
Answer:
phonebook = diet ( )
n = input (“Enter total number of friends”)
i = 1
while i <= n :
a = input (“Enter name”)
b = input (“Enter phone number”)
phonebook [a] = b
i = i + 1
name = input (“Enter name”)
f = 0
l = phonebook.keys( )
for i in 1 :
if (comp (i, name) == 0) :
print (“Phone number =” ,
phonebook[i])
f = 1
if (f == 0) :
print (“name not exist”) [4]

CBSE Sample Papers for Class 11 Informatics Practices Set 3 with Solutions

Question 4.
(a) What is a foreign key?
Answer:
A foreign key is a key used to link two tables together. This is sometimes also called as a referencing key. A Foreign Key is a column or a combination of columns whose values match a Primary Key in a different table.

The relationship between 2 tables matches the Primary Key in one of the tables with a Foreign Key in the second table. If a table has a primary key defined on any field(s), then you cannot have two records having the same value of that field(s). [3]

(b) Help Sameer in predicting the output of the following queries: [3]
(i) SELECT (5 * 2 / 2+8-2) AS ‘FINAL’;
(ii) SELECT (15\% 2+4* 3) AS RESULT;
(iii) SELECT (8*3 / 2+4\right) AS ‘PRINT’;
Answer:
(i) FINAL 11
(ii) RESULT 13
(iii) PRINT 16 [3]

(c) In a multiplex, movies are screened in different auditoriums. One movie can be shown in more than one auditorium. In order to maintain the record of movies, the multiplex maintains a relational database consisting of two relation viz., MOVIE and AUDI respectively as shown below:
MOVIE (MovieID, MovieName, ReleaseDate)
AUDI(AudiNo, MovieID, Seats, ScreenType, TicketPrice)

(i) Is it correct to assign Movie_ID as the primary key in the MOVIE relation? If no, then suggest an appropriate primary key.
(ii) Is it correct to assign AudiNo as the primary key in the AUDI relation? If no, then suggest appropriate primary key.
(iii) Is there any foreign key in any of these relations? [3]
Answer:
(i) Yes, it is correct to assign MovielD as the primary key in the MOVIE relation because primary key uniquely identifies each record in the relation and here MovieID will identify the each record about movie.

(ii) Yes, it is correct to assign AudiNo. as the primary key in the AUDI relation. Here AudiNo. will identify the each record of Auditorium.

(iii) Yes, MovieID is foreign key in Audi relation [3]

(d) Explain the types of SQL statements. [4]
Answer:
SQL statements can be divided into four major categories

(i) Data Manipulation Language (DML):
These statements consist of queries that insert data into tables in a database and statements that change the data in the database. SQL statements under this category are INSERT, UPDATE, DELETE etc.

(ii) Data Definition Language (DDL): These statements define the structure of the database. DDL consists of those statements that create, alter and drop database objects. Statements under this category are CREATE, ALTER, DROP, etc.

(iii) Transaction Control Language (TCL): These commands manage changes made by data manipulation language commands. These commands are COMMIT, ROLLBACK, etc.

(iv) Data Query Language (DQL): The commands of SQL that are used to retrieve data from the database. SQL statement under this category is SELECT [4]

Question 5.
(a) Write one very important feature of relational data model. [1]
OR
What are tables in SQL? [1]
Answer:
The association between rows is represented solely by data values in columns drawn from a common domain. [1]
OR
The table is a collection of record and its information at a single row. [1]

(b) What is degree and cardinality of relation and how are they linked to rows and columns. [2]
Answer:
The number of attributes in a relation is called degree and the number of tuples in a relation is known as cardinality. The rows and columns of a table are known as Tuples and attributes. [2]

(c) Consider the table, CUSTOMER given below and give answer for (i) and (ii): [2]
Table: CUSTOMER

CNO CNAME Address
101 Richa Jain Delhi
102 Surbhi Sinha Chennai
103 Lisa Thomas Bangalore
104 Imran Ali Delhi
105 Roshan Singh Chennai

(i) Identify the degree and cardinality of given table
(ii) Which field should be made the primary key?
Answer:
(i) Degree : 3
Cardinality : 5
(ii) CNO [2]

(d) Consider the table CUSTOMER from Q.No. 5(c) and answer the following questions: [2]
(i) Identify the candidate key(s) from the table CUSTOMER.
(ii) Which command is used to insert new record into table CUSTOMER?
Answer:
(i) CNO, CNAME
(ii) INSERT [2]

(e) Define the following:
(i) Data item
(ii) Record
(iii) Table
(iv) Data redundancy [4]
Answer:
(i) Data item: The smallest unit of named data is called data item. It represents one type of information and is also referred to as a field.
(ii) Record: A named collection of data items that represent a complete unit of information is called a record.
(iii) Table: A group of all logically related records that are given a name is called a table.
(iv) Data redundancy: Data redundancy is duplication of data. [4]

(f) Consider the table EXAM given below:

Name Stipend Subject Average Division
1. Karan 400 English 68 FIRST
2. Aman 680 Mathematics 72 FIRST
3. Javed 500 Accounts 67 FIRST
4. Rahul 200 Informatics 55 SECOND
5. Raunaq 400 History 35 THIRD
6. Kiran 550 Geography 45 THIRD

Write output of SQL commands given below:
(i) SELECT NAME FROM EXAM WHERE AVERAGE > = 70;
Answer:
NAME
Aman

(ii) SELECT NAME, SUBJECT FROM EXAM WHERE Stipend=400;
Answer:
NAME : SUBJECT
Karan  : English
Raunaq : History

(iii) SELECT No, Stipend FROM EXAM WHERE Subject = “Accounts”;
Answer:
No : Stipend
3 : 500

(iv) SELECT Subject FROM EXAM WHERE Division = “THIRD”; [4]
Answer:
Subject
History
Geography

CBSE Sample Papers for Class 11 Informatics Practices Set 3 with Solutions

Question 6.
(a) Write the output for the following codes :
A = {10 :1000, 20 : 2000, 30 : 3000, 40 : 4000, 50 : 5000}
print (A. items ( ))
print (A. key ( ))
print (A. values ( )) [2]
Answer:
(a) Output
[(40, 4000), (10, 1000), (20, 2000), (50, 5000), (30, 3000)]
[40, 10, 20, 50, 30]
[4000, 1000, 2000, 5000, 3000] [2]

(b) Write a Python program to enter two lists and merge them. Also display merged list. [3]
Answer:
list1 = [ ]
num = int (input(‘Number of elements in list1 :’))
for n in range (num) :
numbers = int (input(‘Enter number’))
list1. append (number)
list2 = [ ]
num1 = int (input (‘How many number in list2 :’))
for n in range (num1) :
numbers = int (input(‘Enter number’))
list2. append (number)
marged _ list = listl + list2
print (“Merged List with elements from both lists :”, megred _ list) [3]

Commonly Made Error:
Some students do not use proper indentation in program that give the error.

Answering Tip
Use proper indentation after conditional statements as while, for, if, etc.

(c) Out of the following find those identifiers, which can be used for naming variable or functions in a Python program :
Days*Rent, For, A_price, Grand Total, do, 2 clients, Participantl, _ Mycity [2]
Answer:
For, A_price, do, Participantl, _ Mycity can be used for naming variable or functions in a Python program. [2]

(d) Write a Python program to calculate the area of rectangle. [3]
Answer:
length = int(input(“Enter the length of rectangle :”))
breadth = int(input(“Enter the breadth of rectangle:”))
area = length*breadth
print(“Area of rectangle:”, area)
Output
Enter the length of rectangle : 10
Enter the breadth of rectangle : 14
Area of rectangle : 140 [3]

Question 7.
(a) Explain Advantages of Artificial Intelligence. [2]
Answer:

  • High Speed & Accuracy with fewer errors it takes decisions as per pre experience or information
  • High reliability can perform the same action multiple times with high accuracy
  • Useful for risky areas helpful in situations such as defusing a bomb, exploring the ocean floor, where to employ a human can be risky. [2]

(b) Define block chain technology. [2]
Answer:
(i) The blockchain technology works on the concept of decentralized and shared database where each computer has a copy of the database.

(ii) The most popular application of blockchains technology is in digital currency. However, due to its decentralized nature with openness and security, blockchains are being seen as one of the ways to ensure transparency, accountability and efficiency in business as well as in governance systems. [2]

Case Based Questions (Attempt any 4)

Question 8.
Consider the following dictionary Opposite: [4]
opposite={“Good”: “Bad”, “White”: “Black”, “Up”: “Down”, “Right”: “Wrong”}

(i) To print the opposite of ‘Black’ the code should be:
(A) print (opposite.get(“Black”))
(B) print(opposite[“Black”])
(C) print(opposite[2][1])
(D) None of these
Answer:
(D) None of these

(ii) print (opposite.keys()) will print:
(A) dict_keys([’Good’, ‘White1, ‘Up’, ‘Right’])
(B) dict_values([‘Bad’, ‘Black’, ‘Down1, ’Wrong’])
(C) Error
(D) dict_keys(l,2,3,4)
Answer:
(A) dict_keys([’Good’, ‘White1, ‘Up’, ‘Right’])

(iii) print (len (opposite)) will print:
(A) 8
(B) 4
(C) 33
(D) 10
Answer:
(B) 4

(iv) print (“Wrong” in opposite), the output will be:
(A) True
(B) False
(C) Yes
(D) No
Answer:
(B) False

(v) The output of the segment will be: del opposite [“Good”] print opposite
(A) {‘Good’: Null, ‘White1: ‘Black’, ‘Up’: ‘Down’, ‘Right’: ‘Wrong’}
(B) {Null: ‘Bad’, ‘White’: ‘Black’, ‘Up’: ‘Down’, ‘Right’: ‘Wrong’}
(C) {‘White’: ‘Black’, ‘Up’: ‘Down’, ‘Right’: ‘Wrong’}
(D) wrong statement
Answer:
(C) {‘White’: ‘Black’, ‘Up’: ‘Down’, ‘Right’: ‘Wrong’}